Abstract

Fe-Al bilayer interfaces with and without interface stabilizing layers (Ti, V, Zr) were fabricated using dc magnetron sputtering. Intermixing layer thickness and the effectiveness of the stabilizing layer (Ti, V, Zr) at the interface were studied using Rutherford backscattering spectrometry (RBS) and x-ray reflectometry (XRR). The result for the intermixing thickness of the AlFe layer is always higher when Fe is deposited on Al as compared to when Al is deposited on Fe. By comparing measurements with computer simulations, the thicknesses of the AlFe layers were determined to be 20.6 Å and 41.1 Å for Al/Fe and Fe/Al bilayer systems, respectively. The introduction of Ti and V stabilizing layers at the Fe-Al interface reduced the amount of intermixing between Al and Fe, consistent with the predictions of model calculations. The Zr interlayer, however, was ineffective in stabilizing the Fe-Al interface in spite of the chemical similarities between Ti and Zr. In addition, analysis suggests that the Ti interlayer is not effective in stabilizing the Fe-Al interface when the Ti interlayer is extremely thin for these sputtered metallic films.

Received 24 September 2008Accepted 06 January 2009Published online 04 March 2009

Acknowledgments:

This work was supported by the National Science Foundation (NSF) Grant No. DMR-0516603. The authors would like to thank MMF, Montana State University, Bozeman, MT for providing the facility to prepare samples. A portion of the research was performed at EMSL, a national scientific user facility sponsored by the Department of Energy’s Office of Biology and Environmental Research located at the Pacific Northwest National Laboratory, Richmond, WA.